Not receiving new email address confirmation email

I’m trying to add another email to my profile, however, I’m not receiving the verification email.
It’s quite possible this has nothing to do with Gitlab.

The email address is a catchall on a custom domain which forwards to a Gmail address. I switched my DNS from Cloudflare to Namecheap several days ago. Now that the DNS has propagated, I can receive emails as normal, but I’m still not getting the confirmation email from Gitlab, no matter how many times I resend it.